Telephone system and individual transmitter therefor.



C. L. CHISHOLM.

TELEPHONE SYSTEM AND INDIVIDUAL TRANSMITTER THEREFOR.

APPLICATION FILED MARI l9l0.

Patented Mar. 21, 1916.

2 SHEETSSHEET I.

WZ/Mfilllhfifl, Inventor by r 1 Attorneys 0 l I I 1 uh j I II WitnessesC. L. CHISHOLM.

TELEPHONE SYSTEM AND INDIVIDUAL TRANSMITTER THEREFOR.

APPLICATION FILED MAR. 2I| I910.

1,176,522. Patented Mar. 21,1916.

2 SHEETS-SHEET 2.

a i a I i 5 a i i I I I a I Inventor I I r I t Attorneys CHARLES L.CHISHOLM, OF MARYSVILLE, NEW

BRUNSWICK, CANADA, ASSIGNOR TO CHISHOLM TRANSMITTER & TELEPHONEINSTRUMENTS COMPANY.

TELEPHONE SYSTEM AND INDIVIDUAL TRANSMITTER THEREFOR.

Specification of Letters Patent.

Patented Mar. 21, 1916.

Application filed March 21, 1910. Serial No. 550,624.

To all 2072 0m it may concern Be it known that I, CHARLES LOGAN CrnsIIOLM, a subject of the King of Great Britain and Ireland, residing atMarysville. in New Brunswick. Dominion of Canada. have invented a newand useful Telephone System and Individual Transmitter Therefor, ofwhich the following is a specification.

This invention has reference to improvements in telephone systems andindividual transmitters therefor and its object is to provide atelephone system wherein telephone transmitters may be individual to theusers. the transmitter being portable and readily attachable to anddetachable from freely accessible circuit terminals of transmittercircuits situated at local stations in the telephone svstem, which localstations are each provided with a receiver local thereto and may or maynot be also provided with a transmitter local to the station.

In ordinary telephone stations of a public or semi-public characterthere is constant danger of infection of healthv persons with diseasesdue to the use of the telephones and especially of the transmitters bypersons already having diseases. The transmitter is particularly liableto become infected through being used by diseased persons because of thedeposition of moisture in the mouth piece of the transmitter and uponthe diaphragm during the act of speakint thereinto. and disease germsfind readv lodgment in the mouth piece already moistened and warmed bvuse and upon the diaphragm likewise moistened and warmed. The conditionfor the propagation of disease germs is particularlv favorable in thechamber immediately adjacent to the diaphragm of telephone transmittersin ordinary use, and when the moisture has evaporated such germs arereadily dislodged and may easily reach the mouth and nose of asubsequent user so that a public or semi-public station is. because ofthe transmitter. a constant source of danger to users of the telephone.

Various means have been proposed for eliminating the danger of diseaseinfection on the transmitter side of the telephone unit and such meansusually consist either of protecting devices for the mouth piece to beremoved and destroved after each use of the telephone, ora constantlypresent distransmitter infectant, or some other like expedient, or

an attendant is charged with the duty of cleansing and disinfecting thetelephone after each use. The removable mouth piece protector is more orless of a nuisance to the user and for this reason the emplovment ofsuch a protector is often neglected, and further more such mouth pieceprotectors do not prevent the accumulation of disease germs on thediaphragm. If a germ proof shield be emploved it interferes with theproper and seldom if ever atbecause manv persons ments too large to bereadily stored or trans- 8O ported by the ordinarv user. and furthermorerequiring marked changes in existing telephone installations.

By the present invention the transmitter onlv is individualized to theuser for it is the transmitter that is practically the sole source ofdan er in the use of public tele hcnes. since the danger from thereceiver is almost whollv negligible.

The present invention contemplates not only the features mentioned butother features, resulting in the elimination not only of all the dangersto the health of the users of telephones but of all the disagreeablefeatures of public or semi-public telephones,

all of which will be best understood from a consideration of thefollowing detail description taken in connection with the accompanyingdrawings, in which drawings:

Figure 1 is a diametric section, with parts in elevation of anindividual transmitter as housed in a casing similar to a watch casing,the showing being on a somewhat enlarged scale. Fig. 2 is a view similarto that of Fig. 1 but showing the casing open and the mouth piece of thetransmitter in the operative position. Fig. 3 is a section of thestructure of Fig. 1 on a diameter approximately at right angles to thediameter of the section of Fig. 1. Fig. 4 is a view showing theindividual transm tter without the protecting casing and with anon-collapsible mouth piece. the latter being shown in section. Fig. 5is an elevation of a desk set showing the adaptability cf the individualtransmitter thereto. Fig. 6 is a section, on an enlarged scale ofcircuit terminals used in connection with the present invention. Fig. 7is a section, on an enlarged scale, of the terminal carrying portion ofthe individual transmitter, such terminals being adapted to the localstation terminals illustrated in Fig. 6. Fig. 8 is a diagram of atelephone system showing local stations suitably equipped for the use ofthe individual transmitter. Fig. 9 is an enlarged detail view of aportion of the individual transmitter, with parts in section.

Referring to the drawings and more particularly to Figs. 1, 2 and 3there is shown a casing 1 provided with a cover 2 which may or may notbe hinged to the body of the casing but which is shown in the drawingsas so hinged, and the casing with its cover is in size and shape similarto an ordinary watch case, whereby the structure, when closed, isadapted to be placed in the vest pocket if desired, thus making thetransmitter highly convenient for individual use. Mounted in the casing1 is a transmitter element 3 which may be considered as a granularmicrophrnic element of minute size with the diaphragm and granulechamber substantially coextensive, the sound receiving diaphragm beingof less diameter than the diameter of the bell end of mouth pieces suchas are commonly employed in connection with transmitters. Themicrophonic element 3 is mounted in the casing 1 between the backthereof and a plate t. which may overlie in part the diaphragm of thetransm tter to form a shallow air chamber. It will be understood howeverthat the plate 4 is not absolutely necessary since the microphonicelement may be mounted directly on the inner back wall of the casing 1.Secured to the transmitter element 3 or to the plate 4 wherectnstituting the outer covering for the transmitter element is a mouthpiece 5 which may be screwed or otherwise secured to a boss 6 formed onthe front of the plate 4 and having a passage therethrough so that soundwaves may easily reach the diaphragm in the usual manner.

In order that the transmitter may be readily portable and convenient tothe user it is preferred to form the mouth piece 5 in such manner as tobe easily collapsible and for this purpose it may be made of a spiralWire 7 having a constant tendencytoward the expanded position but whichmay be collapsed in the direction of the axis of generation of thespiral, and this spiral wire support 7 is provided with a covering 8 ofsome suitable flexible material which for the best results should beimpervious to moisture. Soft rubber, oiled silk, and like materials areadapted for this purpose.

The mouth piece 5 may remain on the transmitter and when the cover 2 isclosed onto the body portion 1 of the casing then this month piece willcollapse into very shallow space, but-by forming the wire 7 of elasticmetal, such for instance as piano wire, the mouth piece will have aconstant tendency to assume the operative or expanded position. Thecasing 1 may be provided with a catch 9, push piece 10, and ring 11similar to like parts in watch cases so that when the cover is closeddown on the body portion 1 it will be locked in this position but mayl-e readily released by pressure on the push piece 10 and the cover willthen move to the open position either under the action of a spring suchas is commonly used in watch cases, or by the expansive impulse of themouth piece 5. The ring 11 forms a ready means for attaching the casingto a watch chain or other fastening device so that the user may carrythe device in the pccket without danger of losing it. in the same manneras a watch is carried. The flexible covering of the spiral wire 7 mayeither be inside the spiral or outside the same. or the spiral may behoused in such covering.

In the particular structure shown in the drawings there is mounted inthe casing 1 between the back of the casing and the plate 4, a block 12of insulating material having spaced cavities 13 matching spacedopenings 14 through the rim of the casing at any convenient pointtherearound. but preferably located with reference to the push piece 10in either the six oclock position or the twelve oclock position,considering a watch face as usually mounted in a watch casing.

Centralized in the sockets 13 of the block 12 are pins 15 of conductingmaterial and these pins are connected by suitable conductors 16 to therespecti e electrodes of the microphonic element. The pins 15 thereforeconstitute the terminals of the microphonic element which terminals arelocal to the individual transmitter. The terminals 15 are preferablywithin the confines of the casing 1 so that there is no obtrusiveprojection beyond the casing.

In order to adapt existing telephone systems already installed. or newinstallations, for the use of the individual transmitters, somemodification of such systems is necessary, but where telephone stationsare al ready installed with receivers and transmitters the transmittersalready in place need not be disturbed and provision may be made wherebythe individual transmitter may be used, if desired, or the transmittersalready installed may be used, each without interference from the other.

A telephone system embodying the present invention is illustrated inFig. 8, where there is indicated a central station 17 with telephoneline conductors 18 extending therefrom to various local stations, two ofwhich latter are indicated as suificient to illustrate the system ofthis invention. For convenience of description one of these localstations is designated 19 and the other 20. Each station contains areceiver 21 local thereto. At the station 19 there is installed atransmitter 22 local to this station, and at the station 20 thetransmitter itself is omitted but the transmitter circuit is retained.At station 19 the continuity of the transmitter circuit may be readilybroken at one point and another circuit established around thetransmitter 22 to circuit terminals 23, 24 this new circuit includingthe primary of the usual induction coil 25 and the charging battery 26or other charging source for the transmitter circuit at the localstation.

In the arrangement shown at station 19 a conductor 27 is branched to theterminal 23 and a conductor 28 is branched to the terminal 24 and whenthese terminals are bridged, provision is made for cutting out thetransmitter 22. A terminal structure adapted for the conditions presentat station 19 is illustrated more in detail in Fig. 6, where there isshown a block 29 of insulating material provided with tubularprojections or plugs 30 so shaped and spaced as to readily enter thepassages 13 in the block 12 of an individual transmitter, the plugs 30being made elastic by splitting as indicated at 31 or constructed in anyother manner to readily lock in the passages 13 with out binding thereintoo firmly to interfere with ready removal of the plugs 30 whendesirable. Each plug 30 has a metal tubular lining or sleeve 32 whichmay be also split to render it elastic and this metal lining 32 isdesigned to receive a corresponding pin 15 constituting a circuitterminal of an individual transmitter. The other end of the sleeve 32from that entering a plug 30 may receive a metal plug 33 to which may besoldered or otherwise secured the respective conductor 27 or 28 as thecase may be. The end of the sleeve 32 within the plug 30 stops short ofthe outer end of the plug so that accidental contact therewith isprevented.

Under the conditions present at local station 19 one of the sleeves 32is in electrical connection with a plate or strip 34 traversed by thestem 35 of a plug 36 movable in a passage 37 formed in the block 29 inspaced relation to that lug 30, the conducting sleeve 32 of which isconnected to the conducting plate or strip 34. The end of the stem 35projecting through the plate or strip 34 carries a conducting plate 38to which there is secured a conductor 39 leading to one side of thetransmitter 22. A

spring 40 housed within the passage 37 serves to maintain the block 36in a projected position but this s ring will permit the block 35 to moveinto the passage 37 on the application of suflicient force to compressthe s ring 39, and this will carry the plate 38 out of contact with theplate 34, but under normal conditions electrical contact is maintainedbetween these two plates.

The conductors 28 and 39 constitute portions of the local transmittercircuit at station 19 and this circuit is normally maintained at theplates 34 and 38 by the action of the spring 40 and when the block 36 isundisturbed the telephone transmitter 22 may be utilized in the usualmanner. If however, the block 36 be moved against the action of thespring 40 then the telephone transmitter 22 is cut out of the localtransmitter circuit.

If in an arrangement such as shown at 10- cal station 19 of the systemof Fig. 8, an individual transmitter be applied to the terminals 23 and24 by the introduction of the plugs 30 into the sockets 13, then on theseating of the plugs 30 in said sockets the block 36 is brought intocontact with the casing 1 and the sprin 39 is com ressed thus cuttingout the transmitter local to the local station 19 by the act ofincluding the individual transmitter in the transmitter circuit at saidstation. Under the circumstances assumed it will be seen that either thetransmitter local to the station or the individual transmitter may beused as may be desired. This is particularly valuable in semi-publicstations where the use of the transmitter there located may be confinedto one or more authorized persons while the more general use of thestation will be possible for persons supplied with the individualtransmitters. By this means the danger of contaminating the transmitteror of transmitting diseases is reduced to a negligible minimum.

here it is not desirable to have a telephone transmitter as a permanentfixture at the local station, the switching mechanism composed of theblock 36 and the plates 34 and 38 is omitted and the telephonetransmitter 22 is also omitted, but the local transmitter circuit isretained together with the readily accessible terminals 23 and 24adapted to be inserted in the sockets 13 to complete the circuit to theindividual transmit ter microphonic element through the pins 15. Thisarrangement is shown at station 20 in Fig. 8, At this local stati 20 theconductors 27 and 28 are indicated as forming a flexible cord, and itwill be understood that a flexible cord may or may not be used asdesired, at any or all the stations.

In Fig. 5 there is shown a desk set 41 having readily accessible circuitterminals 23% in the transmitter circuit, and an individual transmitter1 may be readily applied to or removed from these circuit terminals atwill and without the aid of tools, this facility of attachment to andremoval of the individual transmitter from the readily accessibleterminals in the transmitter circuit at the local stations, whatevertype of telephone unit be used together with the ready portability ofthe individual transmitter and its unobtrusive size whereby it isadapted to small pockets such as vest pockets. greatly enhances theusefulness of the individual transmitters.

Vhere the collapsibility of the mouth piece 5 is not of primeimportance, a noncollapsible mouth piece 42, shown in Fig. 4, may beapplied to the transmitter 3 and the latter may replace the transmitter22 of station 19 or may be used as an individual transmitter to beremoved from the readily accessible transmitter circuit terminals andstored away when not in use to prevent others than the owner of theparticular instrument from using the same. In order to provide for theready cleansing of'the diaphragm of the individual transmitter theportion of the plate 4 immediatel overlying the diaphragm is in the formof a. readily removable screw plug 43 shown in Fig. 9.

It will be understood that the arrangement of circuit terminalsdescribed is indicative only, and the showing of the drawings does notpreclude the use of other circuit terminals and other means forconnecting the individual telephone transmitter into a telephone system,whether the local transmitter be present or not, this coupling of theindividual transn'utter into the circuit being possible without the aidof tools and at will.

The individual transmitter being of small size and of few parts isreadily manufactured at small cost and may be sold profitably at a verymoderate price.

One of the principal advantages of the individual transmitter is due toits being strictly sanitary and thereby preventing the establishing ofcenters of infection and the spread of disease, for the use of thetransmitter is confined to one individual.

The invention is particularly useful in connection with telephonesinstalled in hospitals or hotels or public telephone booths or any otherpublic or semi-public place. Persons afflicted with diseases liable tobe transmitted can with the individual transmitter readily usetelephones and have tie satisfaction of knowing that such use is freefrom the. liability of endangering others.

The extreme cleanliness of the individual transmitters will present awelcome relief to those who object from cleanly motives to themiscellaneous use of telephones. There is also another advantage of theindividual transmitter which however is commercial rather than sanitary.By the employment of the individual transmitter the indiscriminate useof the telephone by non-subscribers is prevented since telephone systemsinstalled for use with the individual transmitter only could not be usedby others and the very purpose for which the individualtransmitter isprovided would prevent its be-' ing loaned by the owner to others.

Vhile the particular construction of the microphonic side of theindividual transmit ter, of this invention does not enter into thepresent invention, it may be stated that the transmitter, including thesound receiving diaphragm and the granule chamber, may be less than oneinch in diameter and less than three sixtecnths of an inch in thicknessand the casing inclosing the transmitter need only be sufficiently largeto accommodate the mouth piece when in the collapsed condition and sincethe open end of such mouth piece has been found in practice to operatesuc cessfully when of less diameter than the mouth pieces in common use,the entire structure need not exceed the size of a medium size watch ofthin model.

What is claimed is:

1. A telephone system having stations with telephone receivers andtelephone transmitters local to said stations, the local circuits ofsaid transmitters being each provided with normally accessible circuitterminals bridging the local transmitters, individual telephonetransmitters having circuit terminals adapted to be applied to andremoved from the normally accessible circuit terminals of thetransmitter circuits at the local stations. and means for the electricalelimination of the local telephone transmitters from the localtransmitter circuits on the inclusion of the individual transmitter inthe local telephone transmitter circuit.

2. A telephone system comprising telephone units at local stations andeach provided with circuit terminals for the transmitter circuit inaddition to the transmitters included in the telephone unit, a switch inthe local telephone transmitter circuit movable to electricallyeliminate the local transmitter, and an individual telephone transmitterincludable in and removable from the local transmitter circuit at willand without the aid of tools.

3. In a telephone system, a telephone station having a transmitter and areceiver both local to said station, a telephone transmitter includablein and removable from the local transmitter circuit at will and withoutthe aid ottools, and, means for electrically,

eliminating the local transmitter when the second named transmitter isincluded in the local transmitter circuit.

4. In a telephone system, a telephone station having a transmitter and areceiver both local to said station, a telephone transmitter includablein and removable from the local transmitter circuit, and means forelectrically eliminating the local transmitter when the secondtransmitter is included in the local transmitter circuit comprising aswitch in the first transmitter circuit rcsponsive to the inclusion ofthe second transmitter in the transmitter circuit to break the circuitto said first named transmitter.

5. In a telephone system, a telephone station having a transmitter and areceiver both local to said station, the transmitter bein included in acircuit provided with ascessi ble circuit terminals, and a switchassociated with said circuit terminals, and a telephone transmitter withcircuit terminals matching those at the telephone station and engagingthe switch to open the same on the application of the transmittercarried terminals to the accessible terminals at the station.

6. In a telephone system, a telephone station having a transmitter and areceiver, and suitable circuits local to said station, circuit terminalsincluded in the transmitter circuit, a switch also included in thetransmitter circuit and having a normal tendency to the closed position,said switch being associated with the circuit terminals, and a telephonetransmitter having circuit terminals matching the circuit terminals withwhich the switch is associated and adapted to be connected to andremoved from the local transmitter circuit terminals at will and withoutthe aid of tools, the switch in the local transmitter circuit respondingto the inclusion of the second named transmitter in said circuit to openthe circuit to the first named transmitter.

7. A telephone system comprising a telephone set at a local station, anindividual transmitter includable in and. removable from the transmittercircuit at the local station at will and without the aid of tools, andmeans for rendering the transmitter at the local station inactive whilethe individual transmitter is included in the transmitter circuit atsuch station.

8. A telephone system comprising a telephone set at a local station, anindividual transmitter includable in and removable from the transmittercircuit at the local station at will and without the aid of tools, andmeans for rendering the transmitter at the local station inactive whilethe individual transmitter is included in the transmitter circuit atsuch station and restoring the local transmitter into active relation tothe transmitter circuit when the individual transmitter is removed fromsaid transmitter circuit.

9. A telephone system comprising a telephone set at a local station, anindividual transmitter includable in and removable from the transmittercircuit at the local station at will and without the aid of tools, andmeans for rendering the transmitter at the local station inactive whilethe individual transmitter is included in the transmitter circuit atsuch station and restoring the local transmitter into active relation tothe transmitter circuit when the individual transmitter is removed fromsaid transmitter circuit, said means responding automatically to theinclusion in and removal of the individual transmitter from thetransmitter circuit.

In testimony that I claim the foregoing as my own, I have hereto aiiixedmy signature in the presence of two witnesses.

CHARLES L. CHISHOLM.

Witnesses:

FRAN K B. OCIISENREITER. J. T. LAWSON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

